The continuing development and availability of new communication and control technologies provide a constant source of candidate devices and techniques for improving infrastructure. Wireless mesh network communication is a particularly useful technology for infrastructure application as it is the nature of mesh interconnection, sometimes called a mesh cloud, to impart reliability and redundancy for the communications mission, the very etiology of the network. Mesh networks may be easily instituted to provide high bandwidth communications and network control may be decentralized or centrally managed. Sensor technology also continues to offer new techniques and devices to sense and measure environmental variables and system conditions. Cost for performance continues to decline. Adjuncting both of these technologies is the national treasure of the Global Positioning System (GPS) that provides position information as well as highly accurate time information to its users. Here too, the cost of a receiver for the GPS system has dramatically declined.
Two infrastructures that can immediately benefit from the progress of these technologies are street lighting control and traffic control in large urban areas. Conventional street lighting, such as provided by incandescent, mercury vapor, and even efficient high pressure sodium lamps, consumes significant energy per year and total energy costs can be staggering for large urban areas. For example, Los Angeles currently has approximately 209,000 street lights that use 197,000,000 kilowatt-hours of electricity per annum. A large recurring energy cost such as this continues to motivate more efficient energy lighting systems. With the conversion of street lighting to LED technology, municipal lighting budgets should see very significant reductions in operating and maintenance costs, and some expect that conversion breakeven points may appear in as little as five years.
Improved traffic control systems and techniques should also better husband natural resources. There are about 50 million traffic lights in the US in place at intersections, pedestrian crosswalks, train crossings, and other locations on the roadways. The majority of these are for controlling signalized intersections. A 1995 report of the Center for Transportation Research at the University of Texas, Austin, declared that, in general, “criteria for evaluating the effectiveness of signalized intersections are: (1) minimization of total or stopped delay, (2) reduction of numbers of stops (3) minimizing a combination of delay, and numbers of stops, (4) minimizing fuel consumption, (5) cost-efficiency, and (6) tradeoffs of these factors.” It was estimated in 2002 that motorists in the 85 largest US metropolitan areas suffered delays totaling 3.5 billion hours costing about 5.7 billion gallons of fuel. Increasing the effectiveness of signalized intersections through intelligent traffic control should be of great benefit in improving US fuel usage efficiency.